No More DETENTION!!

The actual problem we are trying to solve is:
Kevin takes a bus from home to school. The bus travels 8 miles west, then turns and travels 8 miles north, then turns and travels 7 miles west to the school. If the bus were able to travel directly from Kevin’s house to the school, along a straight path, how much shorter would the trip be?

In order for it to make sense in the video, we made a few minor changes, resulting in this version:
You take a bus from home to school. The bus travels 8 miles west, then turns and travels 8 miles north, then turns and travels 7 miles west to the school, which is bus A. If the bus travels directly from your house to the school, along a straight path, by Bus B's route, how much shorter would the trip be?